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-«j;r have I,,., I s/.,r,„//v ,ml;:,„.l w,/l, Ihc a,m/./,/, , 
■^MT i,:vc„/cd. Tluy arc „f ihe opuuon lIuH ,1 places AL 
ra™^ Ike Sco/l Legacy Premium, .po and medal. Approv, 

i GENERAL STATEMENT.— The j^is-mVM.vf. 

move by precession from East to West (contrary to the hand: 
of a watcli on the Planisphere;, about 14.4° per 1000 years- 
making a complete revolution around the Ecliptic in about 
25,000 years. Tlie Apsides move from West to East 2.2° 
m average per 1000 years, making a romplcte revolution in about 
iS.ooo years. The Winter SoKlin-, which was in Aphelion ii 
rthern Hemisphere 11,700 years mk<>, meets Aphelion once in 
60 years, and .^8° short of a ( oinplcte revolution. This is th< 
m- fi.r v,T./ I. .11" ),friiicls — s.iinriirncs varying greatly, however, 

'" :i" ' -n .if the \|, i,l-s, which sometimes move for 

1 I ill ii 1.1 .1' r III, 111 ill'. vr ;,i;[ieil, at other times much 

III iiiiin- , h ii,i ,1 111 i();.'i,iil nil, lion. The average for the 



l/ic posilii 
ordinarv stiidi 
'.■ell as '.chh 



id they the: v/o 



ESCRIPTION AND EXPLANATION OF THE 

JPHERE.-riu- .Starry Disk represents so much of the tieavenly 
-. \ i.il.li- hiiiii Liiiiude 40" North, being the whole of the Northei 

I ' I'li" liiiilude 50° South. The ICcliptic and present line 

I 111 'li.iwn upon it, and the jirescnl line of the First 

I 1 111 Ir irpresents the constant ICquinoclial, ami revolves 

■I "iiii I .Mill' , 'I'lir 11111 1, 11., I,, I i.|i!: 1 1 lis, and revolving 

1' I Ill 111 i 1: ill. 'Ill Mil- ])resen: place of 

' "ill" I iiiiliiiii I ml 111,11 1.1 ,1 ;. .,,',,'aL 90° .'^ongitude 

I •■ il' ii.ii.ilul li) two iiii.ill :,i.u liLc crosses .nside the 

"I ! I I '!i I I'll'. The iHesent place of the Aphdion is at 
i I'lilby one such cross (+) OT'toV/'- lh<|Ecliptic. 

' i'i!y-^ ;B^i!ii\^"te.^ \\% ;^nT- ^'ti^\j;^ {,^,? 

•'• ' ''■' •'" "";■' ' !'" ^;'"'l ri|..ino.s. The First 
" ' , " ' '" "•'' • ' "'11 I'l.le to tie Vernal 
■ " ' ' ' ' ' i lie spac-d crosses 



I' I he black rings on 

iiiil"i"UT, July 1 6th and 

I'ln.il movement. By 

Nil ,,,r(h will be carried 
revolution, 12,500 years, 
I complete revolution will 



d.lrls. ,;r-r 



constructed b 



calter noticed. 



'sphere in Seho.n's, Aeademies and Colleo 
I, re. Tins addtlwn /„ the orif;inal invention, fur shvu'ing the changes , ' 
iifle and ingenions. and can he s<? explained as to he readily understood hv 
•less, simplicity, eoirrenienee, neatness and cheapness of the Planisphere, as 
<: Whitall "among ingenious men and women -who make useful invention 
cd February 7, iSSj. H. R. HEYL, Chairman Committee of Science a,. 
the hands of a watch, represent the daily rotation path, beneath the starr> 
vault, of places on the given latitude at those stages of the precessiona 
revolution, and in the aggregate mark out the belt referred to. 'Jo ascertair 
when any star within that belt will come to the zenith, set dividers as before, 
and revolving the Equinoctial from Ms present position as a starting point, 
stop when the free point will reach the star selected. Then count the time 
in thousands of years by the crosses along the Ecliptic, from the starting 
point to the Summer Solstice arm of the Colure bar. At North latitude 40'' 
(designated by a second file-mark on Colure bar), Algol will be found in the 
zenith 200 years hence; Vega, 2,300; Alpha Andromeda, 3,200; Capella, 
3,400; Altair, 8,000; and Polaris within 3" of zenith, 12,700 years hence. 
At the last-mentioned time a zenith will also be reached 7° south of the 
present Equinoctial, culminating r2 hours after Polaris in the Earth^ 
revolutions; and the dweller at this latitude will then enjoy the s; 
of the Southern Heavens as is now had from a standpoint 7° south of the 
equator. Every prominent star in or near the path of the Celestial North 
Pole will, in this precessional revolution, in turn become the Pole 
2,Soo years hence it will be Gamma in Cepheus ; 6,500 years hence. Alpha 
in the same constellation; in 11,800 years, Vega; 19,800 years henc 
will be Alpha Draconis, as it also was 5,200 years ago. Each will be 
Pole-star for several centuries. The position assigned to stars after very long 
periods, however, will in some cases be sensibly modified by their proper 
motions. To find when any starwill become the Pole star, bring the Celestial 
North Pole to the star, and count the time on the Ecliptic as before. 
.«,^ MOTIONS OF THE STARS IN RIGHT ASCENSION 
AND DECLINATION ILLUSTRATED. — The stars, as shown in 
Star Catalogues, are constantly gaining in Right Ascension, that is, in 
istance east of the Vernal Equinox. They have an apparent 

lovement of 1° in about 70 years, except as affected by their own 

proper motions. This apparent motion is caused by the real 

motion of the Vernal Equinox west by precession. For il 

tion, bring the Aphelion arm to rest at the Vernal Equir 
the constant First Meridian (not quite correct, however, as 

and axis of rotation, should be at Celestial North Pole), ana tne gam is a. u. 13,50 
srcn .1;, the stars pass under it and around during the precessional movement. ' ■ ■ - ' 
iiK 1 iKin-e m Declination .also, as noted in Star Catalogues — some stars 
imiviiii.; nuithward and others southward — is at the same-time illustrated. 
Krnicnihenng that gain in Northern Declination is an approach to the 
Celestial North Pole, and gain in Southern Declination is departure there- 
from or approach to the Celestial South Pole, revolve the Equinoctial, and 
see sf.nr. ,',.ming into its circle and so approaching its centre (the Celestial 
), all round from the Summer Solstice, via the Vernal Equinox, ' 

p.assing out or retreating on the other side of the '• 7S°, 3° 
lure divides the stars of the fi 



nittce, aecmnpanied 'by a ^^ 

ami purposes. Ample ci'idence ^% 

well a. hy practical observers in the ^ 

' of\ the Pole Star and in the Right 

r of Astronomy. Your Committee 

fitness for the uses for which it i: 



represenl 



■ION. — Hy revolving the Equii 



North 
to the 
Solstic 



■ml that he be 



. . Attest: WM. H. WAHL, Se. 
■ Leverr 
iquent I 




agrees well with the fact. 

applk;ation of planisphere 

andAphehon tu tlirir ihi'mmi d,, iii ii , 1 i 



and cold 
are carried 
out only to 
the end of the 
Glacial Epoch. 
The process, 
carried out in 
accordance with 
present 

city, finds Winter 
temperature of 
Southern Hemi- 
sphere, where .\phe. 
lion is near mid- 
winter, to be iS° 
Fahr. colder than of 
Northern under simi- 
lar exposures— which 



nil Minimer cooler m the .\orlhcrn HcjuiMiluic 
emisphere. Thence onward the climates of the- 
Jversed. Carry forward the 
• meets Aphelion— about 11, ( 



ished, hon 
midwinter i 
Epoch, the 1 
and directio 
the present. 



Solstii 



hosts, one movii 
the precessional every h.ilf revoli 



Thi: 



app,i 



: north and the other south, 
ion of the Equinoctial. The 
the varying rate of from 1° 

however, and di 



s must lie reversed, and Aphelion niii'-,i l-- ii,, ;, ,1,. , ,,',, 

un shown in the tables for e.ich 10,000 jcars. insicid u( 

midwinter is found t,^' fS''"'"/™'". Present positions and moving backwards, 

aboutTh:following'da e7betr"e A If '" T i^'='"^'«--"-» -'■".■-■"■•"g) -^t 
Si.ooo and 102 n„o •„., """'^'^ ^- ^- \»°o, viz: 10,200, 31,000, 59,000, 
01,000. ana '°'""" years ; the longitude of Aphelion being respectively 
3 two greatest eccentriritv 'r „"^'-" '^'-mentioned date was at the time of 
V:.a:'ZttL:7f1^^^^^^^ ">« Epoch, and central of 

t rapid, to zero at the Solsticial C^in^^ '^^T^J ^'^^^<:':^irZ:le^Vr'' ^ T"^' '"""' 
ae to the real motion of the Pole in the gL.ci.uion shifted .0 th^' S^uTS Ss'^herr^i'iUer^'lva: 
unknown in the Northern, ^n^ f„„.-f„ ._.i ...•__ ,. 



■ibration amounts tc 
1 about 166 years 



Poles. Hence (^except 



of 



'I"'"'" ''■;' ' ■ > ■''""' .i!i 111 . niihin a bre.idth or belt of 47", 

•'"'''; """ '' '"' ' ' ' ill K Plane of the parallel of the place 

'/''■"'■ "1 111 I'f which the .axis of the Ecliptic is 

'"'■'^' "I'l I I " I '■ brought to the zenith of that pkace, 
•""',■" '11- "iilim 110" of that belt, to the right or left, 
L will Ik biuught ,ibove the horizon. At the Polar Circle! I 

&■& "'J> p*^'' " '"° *'^^' «="e'«''"S 'o the pole of ;iie 
^Wj- '^V'P''"^- Approaching nearer the Terrestrial Pole, 
,^^K[j^ i's breadth diminishes 1° on each side for every 



SECULAR CHANGES OF CLIMATE.- Changes of 
temperature, occupying long periods, and alternating between the Northern 
and bouthern Hemispheres, are produced by the combined operation of the 
precessional movement and that of the Apsides, and are dependent for their 
extent upon the eccentricity of the E.arth's orbit. This eccentricity varies 
between e.Ktreme limits of .078 and .003 of the orbit's radius. The Earth's 
Aphelion distance in one case exceeds its perihelion distance by over 
14,000,000 miles; in the other by little more than one-fourth of a million 
In wliicliever Hemisphere midwinter meets Aphelion there 
the popular theory of Mr.- James Croll, a secular refrigeratio 



and less 



at the time, by increase both in length 
■ other Hemisphere, a proiiortionate shor 



Imost 
climnies r,.-„-h,Jl ,1 ' ," '"''^^'^ ''"'' vegetation of Itmijerate 

was from 'n'f ''"°" '° 'j'" ^"'^ The cyde of these changes 
next ntTieZc '? °'^ ■"■dwinter with Aphelion to the 

Li 1 P^-ff "°"'''' revolutions. The glaciation of S 
ev^nsi^ '■ "^ r' "'^ '=^'' ''^ "»"^h ligh 
limp „f L,l!^i, L ■"^■' ^" ^^^y 'vay of arriving at tli 
movement inHlc„-"'H'i,'°"l'' '° ^'ve Aphelion abtut the 
movement indicated by the tables for the period for at 

in "'' ' ""V^'J '■' "°' ''"°*"). and ho' ding i to 
according to 'lie P ace revolve the Equinoctial for the same period 
proportionate •;>"d 'hen adjust back or forward —giving each its 
till the conjunction is 




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